At least some content in this article is derived from information featured in the latest update of Pottermore. As such, spoilers will be present within the article. Please take care when reading this article if you have not yet been through the latest update.

"There was a flash of blinding green light and a rushing sound, as though a vast, invisible something was soaring through the air — instantaneously the spider rolled over onto its back, unmarked, but unmistakably dead"

The Killing Curse (Avada Kedavra) is a tool of the Dark Arts and one of the three Unforgivable Curses. It is one of the most powerful and sinister spells known to wizardkind. When cast successfully on a living person or creature, the curse causes instantaneous death.

The only known counter-spell is sacrificial protection, which uses the magic of love. However, one may dodge the green bolt, block it with a physical barrier or by the use of Priori Incantatem. The Killing Curse is an "unblockable" curse, thus Shield Charms won't defend against it. An explosion or green fire may result if the spell hits something other than a living target.

Contents

History

Creation

The Killing Curse was invented during the early Middle Ages by Dark witches or wizards. The curse was created primarily as a means of quickly and efficiently slaying one's opponent in a duel.[3]

Legal status

Along with the Cruciatus and Imperius curses, the Killing Curse is known as one of the most terrible curses in the wizarding world. After the Wizards' Council was reformed into the Ministry of Magic tighter restrictions were placed on the use of certain kinds of magic. The Killing Curse was deemed by the Ministry to be Dark magic and along with the Cruciatus and Imperius curses, were declared "unforgivable" in 1717, with the Killing Curse considered to be the most deadly of the three. Cursing another human with the Killing Curse would carry the punishment of a life sentence in Azkaban.

It should be noted that despite the curse being illegal, references have been made to Aurors using deadly force against opponents, though whether this means they were authorised to use the killing curse specifically is unclear. Despite the circumstances, it is unknown whether the Killing Curse was used by anyone but Voldemort and his Death Eaters during the Battle of Hogwarts. It is also known that use of this curse may go unpunished if there is sufficient evidence that the caster did so under the influence of the Imperius Curse.

Nature

The flash of green light that indicates the Killing Curse

The Avada Kedavra curse is recognisable by the flash of green light and the rushing noise emitted from the caster's wand. When the curse hits a living, organic target it invariably kills them without injury. However, when this curse hits an inanimate target the effect varies: it can produce small fires,[4] small greenish explosions,[5] or explosions of such intensity that can blow up an entire story of a cottage.[6] It is known by most wizards as Lord Voldemort's signature spell. It is possible to intercept the curse with other spells, but this is extremely difficult as it requires the energy jets of the two spells to collide. As the energy jets of virtually all spells are very small and fast, this has only ever been recorded as occurring by accident.

However, certain objects, such as the centaur statue of the Fountain of Magical Brethren, managed to block the curse without any visible damage to itself.[7] It should be noted that curse did not terminate the animation of (i.e. "kill") the statue, however, the statue was only animated by magic and so presumably had no real life in him for the curse to take away.

Performance

"Avada Kedavra's a curse that needs a powerful bit of magic behind it — you could all get your wands out and point them at me and say the words, and I doubt I'd get so much as a nosebleed."

The curse requires great skill in order to be performed correctly. In 1994, Barty Crouch, Jr., disguised as Alastor Moody, claimed that, if all of the students before him were to get out their wands and perform it on him at one time, he would likely be completely unaffected. However, as his loyalties were with Lord Voldemort, it is unknown to what extent his words were accurate. However, in 1997 Severus Snape also stated that to cast Unforgivable Curses you need nerve and ability. It is possible to cast the curse non-verbally, as Bellatrix killed a fox without incantation. However, the lack of the incantation may have been for suspense. Whether this is true or not in Bellatrix's case is unknown.[8] However, during his duel with Dumbledore, Voldemort used this spell several times without an incantation. Intense concentration is likely required to cast the Killing Curse, which is probably why Death Eaters don't use it as their primary offensive spell (although Thorfinn Rowle did launch the curse repeatedly all over the place during the Battle of the Astronomy Tower).

Signs

The Killing Curse is described as a jet or flash of blinding green light that "illuminates every corner of the room"[9] followed by a rushing sound, which causes the victim instant death. Victims of the Killing Curse are identified by the fact that they simply appear to have dropped dead for no biological reason. Indeed, victims seem "perfectly healthy" apart from the fact that they are dead.[8] This lack of visible injuries is one that had confused Muggles throughout the years of its use, requiring many Ministry of Magic officials to modify memories.

Sensation

Presumably, the Killing Curse does not inflict any pain on its target, since it causes instantaneous death. However, Harry Potter, awaking after a Killing Curse cast by Lord Voldemort hit him, describes the sensation as an "iron-clad punch", though it may have also been as a result of his horcrux being destroyed simultaneously.

Survivability

"Not pleasant. And there's no countercurse. There's no blocking it. Only one known person has ever survived it, and he's sitting right in front of me."

The Killing Curse is known to be unblockable, as once it strikes the living victim, it almost always results in immediate death. There is "no counter-curse" since it is not possible to revive the dead. However there are some exceptions:

Sacrificial Protection

The most effective method of surviving the Killing Curse is through Sacrificial Protection. The sacrifice of one's life for another, a manifestation of the powerful magic of love, is the most potent defence against the "unblockable" Killing Curse. Harry Potter was saved by his mother, Lily, who lovinglysacrificed herself when she shielded her son with her body,[10] making him the first known survivor of this Curse. Harry was the only person known to have survived Avada Kedavra with no ill effects, aside from attaining a scar.

Horcruxes

Lord Voldemort's Horcruxes.

Another defence employed against the Killing Curse is the creation of at least one Horcrux. The creation of Horcruxes is a preventive measure, created by a wizard long before he faces an actual Killing Curse attack. However, this is less effective than Sacrificial Protection, since it only allows a little more than the soul of the target to live, while the target's body still dies. If one has Horcruxes, they will not be dead, but they will barely be alive and will be reduced, as Voldemort was when the Killing Curse backfired with his attempt to kill Harry in 1981: to living off another, drinking Unicorn Blood, using the Philosopher's Stone (before it was destroyed), and creating a rudimentary body from Unicorn Blood and Nagini's venom.

Voldemort's Horcruxes tethered his soul to life. The Curse drove his mangled soul from his body and split his unstable soul, leaving him to roam only as a shadowy spirit, unable to move on to death but is a less-than-alive life form. If possible, one can make a Regeneration potion to came back to life, but it requires the bone of the father, the flesh of the servant, and the blood of an enemy. Because Voldemort required a servant to perform the rites of his rebirth, he was forced to spend thirteen years in hiding as he had no one who would come to his aid for such time.

Upon the destruction of all his Horcruxes, Voldemort had no more defence against death, and was finally killed by his own deflected Killing Curse.

Blocking the Curse

Priori Incantatem

The Priori Incantatem effect is when two wands that share the same cores are put into battle against each other. One wand will then force the other wand to repeat its previously-cast spells.

Because of this, an Avada Kedavra Curse can be blocked if a wand that shares the killer's wand's core fires a spell at it: both spells will connect and thus the wizard has been spared by the Killing Curse.

Priori Incantatem occurred in the duel between Harry and Voldemort in the graveyard during Harry's fourth year.[1] Voldemort cast the Killing Curse and Harry cast the Disarming Charm, and because their wands had twin cores, Priori Incantantem occurred; Harry was not killed and was able to hold Voldemort off to give him time to escape.

Phoenixes

Fawkes the Phoenix bursting into flames and then regrowing from the ashes

Phoenixes are semi-protected from the Killing Curse, due to them being immortal. In 1996, Fawkes swallowed one intended for Albus Dumbledore, causing him to burst into flame and die instantly. However, he then was reborn from his ashes.[7]

Stunning Spell

The spell can be directly countered using a Stunning Spell, in which case red and green jets of light will meet and create multi-coloured sparks. Since neither spell is able to reach its intended target, neither will have any effect, as the jets of light basically explode on each other. However, this is particularly tricky, as it requires both jets of light to collide with one another. It is unknown whether this is limited to the Stunning Spell or if it is possible to reflect the Curse with other spells, although during Harry and Voldemort's final duel a similar thing happened when Harry's Disarming Charm collided with Voldemort's Killing Curse, although the Elder Wand's allegiance to Harry must be taken into consideration in this particular situation.

Other targets and dodging

If another target is placed between the caster and the targeted individual, then the new target will take the hit of the Killing Curse, which may simply result in an object being destroyed or damaged. One can also avoid the effects simply by dodging or if the caster has poor aim, as with many attacking curses of this type, the spell must be directly targeted at the intended victim.

Known practitioners and victims

"Avada Kedavra!" The green light filled the cramped hallway, it lit the pram pushed against the wall, it made the banisters glow like lighting rods, and James Potter fell like a marionette whose strings were cut..."

Other practitioners

Etymology

Avada Kedavra is based on the Aramaic אַבַדָא כְּדַברָא, avada kedavra, meaning "let the thing be destroyed". J. K. Rowling confirmed this during an audience interview at the Edinburgh Book Festival on 15 April, 2004, where she had this to say about the spell's etymology: "Does anyone know where avada kedavra came from? It is an ancient spell in Aramaic, and it is the original of abracadabra, which means 'let the thing be destroyed.' Originally, it was used to cure illness and the 'thing' was the illness, but I decided to make it the 'thing' as in the person standing in front of me. I take a lot of liberties with things like that. I twist them round and make them mine."[11]

"Kedavra" also sounds very similar to the English word cadaver, which means "corpse," and derives from the Latin cadere, "to fall."[13]

Behind the scenes

The Killing Curse in LEGO Harry Potter

In the movies the curse has been seen as a jet, a flash, or a burst of green or turquoise light.

The biological reasons for the victim's death have never been fully explained. In any case, it is something that does not affect the health of the victims, as Muggle autopsy show that there is no change aside from outright death. It may simply be that the Curse just causes every organ in the body to instantaneously "shut down".

In Harry Potter and the Prisoner of Azkaban, Sirius Black and Remus Lupin intended to kill Peter Pettigrew for his betrayal of James and Lily Potter. It is unknown how they wanted to do it, possibly by the use of this curse. If it would have been used, Peter would have died the same way as his former friends.

Out of the three, the Killing Curse is the only Unforgivable Curse that Harry did not use.

After Harry Potter survived a second killing curse, he described it as having left a bruise that felt like an "iron-clad punch."

In Harry Potter and the Deathly Hallows: Part 1, After being warned by Kingsley's Patronus and the Death Eaters arrive, an unidentified Death Eater appears and immediately attacks an unidentified Auror with what appears to be a Killing Curse, which causes the Auror to be blasted off his feet and into the wedding cake.

While the curse is noted to be unblockable, there are many exceptions listed: the seventh book shows jets of red and green light colliding and shooting off into multi-coloured sparks, much like fireworks, while the films show it being blocked with a Shield Charm.

In Harry Potter and the Deathly Hallows: Part 2, Ron Weasley casts a green spell in an attempt to kill Voldemort's snake Nagini (one of his Horcruxes). Though if this was indeed the Killing Curse that Ron used against Nagini she would have been destroyed as Horcruxes can be destroyed by being hit with a Killing Curse. This is proven when Harry surrenders to Voldemort and he is hit with the curse, while Harry was "killed", Voldemort simultaneously destroyed the Horcrux that resided in Harry's body.

In Harry Potter and the Deathly Hallows: Part 2, the Killing Curse rebounds on Voldemort during his duel with Harry by the green light of the curse emitting through the crack in the Elder Wand, causing Voldemort's hand to turn black and spread, leading to his death.

The curse's incantation was Voldemort's last words in life in the novel.

Worth noticing is the similarity between the hand movements for the Curse and the shape of Harry's scar; both resemble lightning bolts. It may explain why the scar bore that specific shape instead of just a straight line or anything else.